A Phase 4 interventional study of Isoniazid in Tuberculosis and HIV Infections, sponsored by Centers for Disease Control and Prevention. Completed at 1 site in Botswana. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-27.
Sponsored by Centers for Disease Control and Prevention · Phase 4, Interventional, and Prevention
This is a randomized, blinded, two-arm comparative trial of continued versus limited isoniazid (INH) tuberculosis (TB) preventive therapy in HIV-infected adults in Gaborone and Francistown, Botswana. Subjects will be accrued over two years and followed for a minimum of 36 months.
Randomized, double blinded, two-arm comparative trial of continuous vs. limited isoniazid preventive therapy in HIV-infected adults in Gaborone and Francistown, Botswana. Subjects will be accrued over two years and followed for a minimum of 36 months.
1,170 studies on the registry are indexed under Tuberculosis; 175 are open to participants now.
This study's enrollment of 1,995 is above the median of 150 across 820 interventional studies indexed under Tuberculosis.
Browse Tuberculosis studies →Centers for Disease Control and Prevention is the lead sponsor of 275 studies on the registry; 2 are open to participants now.
Of its 11 completed or terminated interventional studies of FDA-regulated products, 8 (73%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Laboratory:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Absolute neutrophil count (ANC)
The number of neutrophils, white blood cells that help fight infection, in a given amount of blood. Too few raises the risk of infection.
It is a count, not a percentage of the white cells. Limits are written in units that mean the same: ≥ 1.5 × 10⁹/L is ≥ 1,500 per mm³ (µL). Each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Karnofsky performance status (KPS)
A 0–100 scale of how well someone can carry out everyday activities. 100 is no complaints and no signs of illness; 70 is able to look after yourself but not to work or keep up normal activity; 50 is needing considerable help and frequent medical care.
Studies often ask for 60 or 70 and above. Your doctor gives the score.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The treatment (experimental arm) will receive 6 months of open label isoniazid before beginning coded medication (isoniazid).
Drug: Isoniazid
Participants receive 6 months of open-label isoniazid followed by 30 months of placebo (coded medication).
Drug: Isoniazid
Daily 300 mg isoniazid supplemented with 25 mg pyridoxine for 6 months vs 36 months.
Also known as: Isonicotinic Acid Hydrazide
Number of Participants With Incident Tuberculosis
Incident tuberculosis during follow-up. Tuberculosis cases were categorized as: Definite: ≥1 positive culture for M. tuberculosis or ≥2 sputum smears positive for acid-fast bacilli; Probable: 1 sputum smear or biopsy specimen positive for acid-fast bacilli; Possible: clinical diagnosis with negative or unavailable smear/culture results. Outcome data include definite, probable, and possible tuberculosis cases combined, consistent with the published analysis.
Time frame: During follow-up (36 months)
Number of Participants Who Died
All-cause mortality during the 36-month follow-up period.
Time frame: During follow-up (36 months)
Tuberculosis and Death Composite Outcome
Composite of incident tuberculosis and all deaths during the 36-month follow-up period. The paper presents this as "Tuberculosis and all deaths."
Time frame: During follow-up (36 months)
| Milestone | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm |
|---|---|---|
| Started | 1006 | 989 |
| Completed | 851 | 827 |
| Not completed | 155 | 162 |
Incident tuberculosis during follow-up. Tuberculosis cases were categorized as: Definite: ≥1 positive culture for M. tuberculosis or ≥2 sputum smears positive for acid-fast bacilli; Probable: 1 sputum smear or biopsy specimen positive for acid-fast bacilli; Possible: clinical diagnosis with negative or unavailable smear/culture results. Outcome data include definite, probable, and possible tuberculosis cases combined, consistent with the published analysis.
| Participants | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm |
|---|---|---|
| Number of Participants With Incident Tuberculosis | 20 | 34 |
All-cause mortality during the 36-month follow-up period.
| Participants | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm |
|---|---|---|
| Number of Participants Who Died | 39 | 38 |
Composite of incident tuberculosis and all deaths during the 36-month follow-up period. The paper presents this as "Tuberculosis and all deaths."
| Participants | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm |
|---|---|---|
| Tuberculosis and Death Composite Outcome | 59 | 72 |
Collected over From initiation of study medication through 36 months of follow-up. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Continuous Isoniazid Arm | 39/1,006 (3.9%) | 9/1,006 (0.9%) | 0/1,006 (0%) |
| Limited (Placebo) Isoniazid Arm | 38/989 (3.8%) | 6/989 (0.6%) | 0/989 (0%) |
| Event | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm |
|---|---|---|
| HepatitisHepatobiliary disorders | 9/1006 | 6/989 |
| RashSkin and subcutaneous tissue disorders | 1/1006 | 1/989 |
| SeizureNervous system disorders | 1/1006 | 0/989 |
| Peripheral NeuropathyNervous system disorders | 1/1006 | 0/989 |
| Age, Categorical(Participants) | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 1006 | 989 | 1995 |
| >=65 years | 0 | 0 | 0 |
| Sex: Female, Male(Participants) | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm | Total |
|---|---|---|---|
| Female | 715 | 721 | 1436 |
| Male | 291 | 268 | 559 |
| Race (NIH/OMB)(Participants) | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 0 | 0 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 1006 | 989 | 1995 |
| White | 0 | 0 | 0 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Region of Enrollment(Participants) | Continuous Isoniazid Arm | Limited (Placebo) Isoniazid Arm | Total |
|---|---|---|---|
| Botswana | 1006 | 989 | 1995 |
PDFs hosted by the registry, ClinicalTrials.gov.
The record gives a start of Nov 2004, a primary completion of Jul 2009 and a completion of May 2011. It does not say whether these dates are actual or estimated.
Results were first posted in May 2026, 16 years 10 months after primary completion.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Isoniazid
Centers for Disease Control and Prevention →